Spray nozzle



July 21, 1953 D. J. PEEPS SPRAY NOZZLE Filed Sept. 13, 1950 INVENTORDONALD J. PEEPS ATTORN EY Patented July 21, 1953 s 2,646,313 H SPRAYNOZZLE Donald J. Peeps, Toledo, Ohio, assignorto The De Vilbiss Company,Toledo, Ohio, a corporation of Ohio Application September 13, 1950,Serial No. 184,538

This invention relates to spray nozzles: utilizing air for atomizationand particularly to such 7 41102 185 in which; a plurality of air jetsare di-. rected toward the stream of discharged material to atomize itand to form it into a desired pattern. I

-' 4 Claims. (01. 299-1401) In the conventional spray nozzleof this asused for spray coating furniture, automobile bodies and the like, thereis an annular air outlet opening around a circular spray materialoutlet. The purpose of the air from this annular open ing is theprimary'atomization of the material. It also serves as a protectiveshield around the atomized material and prevents an uncontrolleddispersion of the material by the impingement of supplemental air jets.Prior to being subjected -to the action of supplemental air jets thesprayed material has a forwardly flaring conical form.

' To shape the spray discharge'into a more effective fan pattern, it haslong been customary to have a pair of forwardly converging air jetsstrike the centrallair and material stream upon opposite sides.

Various otherfair jets areused at'the sides of the center stream. 90about its axisfrom the sides against which the flattening jets strike.These auxiliary yets have been utilized for two principal purposes.Patents 1,990,824 and 2,029,423 oneof these purposes is to provideastream of air parallel to the axis of the central stream of atomizedmaterial to restrict its lateral spread.

The other .principal'purpose of such side jets v is to improveatomization by directlyimpinging the atomized material stream at itscenter and strongly indenting it. Theus'ual effect from this action isto form the stream intola' cross section of a'rather dumbbell outlineelongated in the plane of the main flattening jetS. It is not believedthat the use of such auxiliary side jets 46 has extended beyond thesetwo arrangements.

To a person not experienced in the art it may 7 appear a simple maneuverto add and arrange variously angled air jets upon a spray nozzle. Thecontrary is actually the case. The size and position of each of the jetsnow commonly utilized are most critical. 'Any disarrangement ordinari-1y has a most harmful effect upon the atomization, the distribution ofthe atomized particles or upon the undesirable deposit of strayparticles upon the face of the spray nozzle. Attempts at variations areaccordingly made with great caution and the creations of new forms arevery infrequent. 1 7

Instead of center piercing and partial division As disclosed inGustafsson V of the main spray material stream, the subject inventionundertakes an entirely new action through the use of an opposed pair oftwo side- .by-side auxiliary jets directed in parallel paths andstriking the central stream at an acute angle and at off center spacedpoints. A flattening as well as a compound indenting action is I thussecured.

Contrary to previous concepts the use of such cooperating jetscontributes to the final formation .of a particularly well atomized anddistributed spray pattern and at the same time does not cause anobjectionable accumulation of stray spray particles upon the face of thespray nozzle.

The contour of the surface in which the aux- "iliary air jet ports arelocated as incorporated in the subject spray nozzle is also considerednovel anda factor in its improved performance. The'port's of theside.atomizing, jets are positioned in an inwardly angled annular surface,while other auxiliary jet ports between the ports of the main flatteningjets and the center orifice are disposed in arcuate outlined fiatsurfaces perpendicular to the axis of-the center orifice.

Such auxiliary jets have been referred to as clean-up jets.

The primary object of this invention 'is the provision of a spray nozzleof superior atomizing power.

A further" object is the provision of a spray nozzle which may beconstructed with less need of. close tolerances. 7

Other objects and features of novelty will become apparent from thefollowing specification with reference to the accompanying drawing inwhich:v I a Fig. 1 is a front view of a spray nozzle embodying myinvention;

- Fig.2 is a central vertical section thereof;

Fig. 3 is an enlarged fragmentaryhorizontal section taken on line 33 ofFig. 1; and

Fig. 4' is a side elevation of the spray nozzle turned 90 about its axisfrom its position in Fig. 2.

Referring to the drawing, my invention is shown as applied to a spraynozzle l with a central orifice 2.

Into this orifice extends a spray material tip 3, as shown in Figure 2.A needle valve 4 is the conventional member for "controlling thedischarge of spray material from tip 3.

The primary atomizing air travels through space 5 surrounding tip 3 andissues from the spray nozzle through the annular opening formed by theperipheral portion of orifice 2 bordering the forward end of the tip 3.This air atomizes the discharged spray material and in commingledrelation therewith travels forwardly in a gradually expanding conicalstream.

From horns 6 and 1 pairs of converging flattening jets are dischargedfrom ports 8, 9, l and H against the atomized material stream to shapethe stream into its final fan pattern.

Encircling the central orifice 2 is an annular ridge I2 approximately.042 inch in height and having a narrow forwardly facing fiat top 13.

Its outer wall I4 is substantially parallel with the axis of the centralorifice 2 while its inner wall surface 15 is tapered at about 53 degreestoward the axis.

In front of each horn the ridge I2 is intercepted by an arcuate shapedcut-out section (16 and I1). These are fiat bottomed and in each is anair port (18 an 9) for discharging a cleanup jet in a path parallel toor inclined slightly toward the axis ofthe center orifice.

On opposite sides of the center orifice -2'and on the inner sloping sidei of the ridge- !2, at points 90 degrees around the center orifice fromthe cut-out sections it and it, are pairs of side by-side ports 20, 25,22 and 23. ihese are positioned to project air jets in parallel pathsagainst the central atomized material stream'at an angle and instraddling relation to the center line of the stream.

Having the surfaces from which these jets are emitted elevated inrelation to the center orifice is particularly advantageous. Theemission point of each jet is thereby brought closer to the stream ofatomized material and the concentration and power of the jet is lessdissipated through expansion before striking the stream. Further,because the surface surrounding each of the ports of these jets issubstantially perpendicular to the port axis, the contour of the portremains fully circular and one side of the air jet is not confined bythe port wall longer than is the other side. t may be readily understoodthat when the port axis is angled to the surface surrounding the port,the outline of the latter is elliptical instead of circular and the airjet becomes asymmetrical due to expansion of that side portion firstreaching. the atmosphere.

In one form of my invention with which excellent results may be obtainedthe more forward Y port in each horn (8 and i0) is .0465 of an inch indiameter and is directed at an angle of 65 degrees toward the axis ofthe center stream; and the rearward horn ports (e and l I) arev .070 ofan inch in diameter and are directed at'an angle of 50 degrees towardthe center stream. The clean-up jets from ports [8 and 19 are .024 indiameter and, are directed in paths. inclined at an angle of 5 degreestoward the axis of the center stream. The side atomizing jet from ports20, 2|, 22 and 23 are .021 in diameter and are angled toward the centerstream axis at 37 degrees. The ports of each pair of atomizing jets are.050 of an inch apart from center to center.

My copending application Ser. No. 190,952, filed October 19, 1950,similarly entitled Spray Nozzle relates to a diiferent form of the basicfeature of striking the central streamv near its source on oppositesides with a plurality of non-merging jets. Instead of having the jetsdirected along parallel paths as in this application the jets 'of thiscopending application are directed along converging paths. The jetshowever separately impinge against the central stream before their pathsintersect.

While a certain embodiment of the invention has been described in detailmodification in respect to the size and angle of air port may be madetherein without departing from the essence "of the invention.

Having thus described the invention, what is claimedas newand desired tobe secured by Letters Patent is:

1. A spray nozzle having a central port for the discharge of anexpanding conical stream of material and air; pairs of atomizing airports on opposite sides of but adjacent to the central portsymmetrically arranged for directing against the stream of material andair near its source from each side a pair of jets along parallel pathswhich are in straddling relation to the axis of the central orifice, andtwo sets of larger ports, farther from the central port and on oppositesides about the axis of the central port from the position of theatomizing air ports, for discharging opposed sets of converging air jetsto strike the stream simultaneously from opposite sides to form it intoits final fan shape.

2. A spray nozzle as set forth in claim 1 in which the atomizing airports are equidistant from the central port.

3. A spray nozzle as set forth in claim 1 in which the jets from thea'tomizing air ports are directed against the stream at an angle of ap-References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,751,787 Binks a Mar. 25, 1930 2,019,941 Tracy a; Nov. 5,19352,271,779 Peeps Feb. 3, 1942 2,303,280 Jenkins c Nov. 24, 1942 2,511,626Einbecker .1 June 13, 1950

